Spectroscopic Investigation of the Remote C-H Allylation of Amides via Photoredox and Nickel Dual Catalysis

The mechanistic details of a reported allylation reaction were investigated by means of Stern-Volmer experiments and nanosecond transient absorption spectroscopy. Both reference substrates, i.e. allylic chloride and trifluoroacetamide, were inefficient quenchers but large quenching rate constants were observed upon the addition of Ni(COD)2 and bisoxazoline. The large quenching rate constants and absence of observable photoproducts were consistent with a mechanism that operates by energy transfer between the excited-state iridium photosensitizer and the nickel complex.